Infrared has been used in communications links to carry voice and data information from a remote location to a central communications or data center. Such wireless links allow data exchange and monitoring of machine operations. One such system is disclosed in the publication OPTICAL SPECTRA, December 1979, pages 17-22.
Infrared has also been used in inventory systems in which bar codes are read and the data therefrom transmitted to a computer, or in systems that provide communication between a programmable controller and machinery. Such a system identified as LIGHTLINK is briefly disclosed in a system specification sheet published by CYPLEX, a division of CONTROLONICS CORPORATION of Chelmsford, Ma.
Other infrared linked computer systems have been disclosed in the prior art, but for the most part the systems are for simple communications, or for sending data to a central control station, or transmitting control data from a controller to send motion control data to operating machinery.